Doable - see the archives
I searched the 27_75-84 archives using "traveler cabin roof" and found most of our discussions on this issue over the past few years. I recommend you read through the discussions. A few summary thoughts include:- You can do it without big problems.- Backing plates in the cabin below the liner are required. (If you had the set-up with the mainshet led to blocks on either side of the cabin roof, you might find embedded aluminum plates - but (like us) your traveler is at the aft of the cockpit.)- Check with Harken and/or Garhauer for design advice as well as hardware recommendations.- Even with multiple attachments to the boom to spread the load, you are adding to the stress on the spar, and reducing your ability to control twist of the main.We took a long hard look, and decided to leave the traveler where it is. Island Nautical did a nice rail-mounted bimini that extends as far forward as the end of the boom, and we are pretty happy with this set-up. (Works great sailing away from the sun, and the sails offer shade heading into it.DavidLady Lillie